1. Field of the Invention
The present invention relates to a radiographic image capturing system which applies a radiation to an object to be examined thereby to acquire a stereoscopic image of the object, and a bioptic method which uses such a radiographic image capturing system.
2. Description of the Related Art
Heretofore, there has widely been carried out a bioptic method which uses a radiographic image capturing system. The bioptic method comprises applying a radiation to an object to be examined thereby to acquire a stereoscopic image of the object, calculating a three-dimensional coordinate position of a bioptic region (e.g., a lesion in a breast) in the object from the stereoscopic image, inserting a bioptic needle into the object based on the calculated three-dimensional coordinate position, and sampling a tissue of the bioptic region in the object under suction with a sampler (opening) of the bioptic needle (for details, see Japanese Laid-Open Patent Publication No. 2010-110418, Japanese Laid-Open Patent Publication No. 2010-075316, and Japanese Laid-Open Patent Publication 2010-075317).
In order to sample a tissue of the bioptic region in the bioptic method, it is necessary to recognize the exact positional relationship between the bioptic needle as inserted into the object to be examined and the bioptic region, and place the opening of the bioptic needle in the vicinity of the bioptic region (e.g., at a position facing the bioptic region) based on the recognized positional relationship.
According to a known process of recognizing the above positional relationship, while the bioptic needle is being inserted in the object to be examined, a radiation is applied to the object to acquire a tomosynthetic image thereof, and the position of the bioptic needle with respect to the bioptic region (area to be examined) is specified from the tomosynthetic image (for details, see Japanese Laid-Open Patent Publication No. 2009-526618).
In connection with brain tumor surgery and surgery with catheterization, there is known a process of generating a three-dimensional image of the patient using a CT (Computerized Tomography) apparatus and displaying the tip end of a probe (catheter) in the three-dimensional image in order to recognize the exact position of the probe in the patient (for details, see Japanese Laid-Open Patent Publication No. 2005-518854 and Japanese Laid-Open Patent Publication No. 2000-175897).
In the process disclosed in Japanese Laid-Open Patent Publication No. 2009-526618, the positional relationship between the bioptic needle and the bioptic region in the tomosynthetic image is different from an actual positional relationship in a three-dimensional coordinate system. Therefore, the radiological technician or doctor (hereinafter referred to as “technician or the like”) who is in charge needs to interpret the tomosynthetic image and determine the positional relationship between the bioptic needle and the bioptic region in the three-dimensional coordinate system from the tomosynthetic image. The positional relationship thus determined may vary in its accuracy depending on the experience of the technician or the like. As a result, a tissue of the bioptic region may not be reliably sampled.
According to the process disclosed in Japanese Laid-Open Patent Publication No. 2005-518854 and Japanese Laid-Open Patent Publication No. 2000-175897, the process of generating a three-dimensional image is liable to require a complex processing sequence and a complex control system.